This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Effect of Epoxy-Based Structural Foam on Energy Management: An Experimental & Analytical Investigation
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 05, 2001 by SAE International in United States
Annotation ability available
Event: SAE 2001 World Congress
The effect of epoxy-based structural foam on strength, stiffness, and energy absorption of foam filled structural components is investigated and implemented to formulate design guide-lines that can be used in enhancing weight reduction and engineering functions of systems.
An experimental approach is first utilized to identify design variables such as foam density, gage, and foam layer thickness, that are needed to enhance the weight/ performance ratio of structural hat-section components. A CAE approach using non-linear, large deformation finite element analysis is used to model the hat-section components. An acceptance level of confidence in the CAE analytical tools is then established based on comparisons of results between the two approaches. Upon that, the CAE analytical tools are deployed in a sensitivity study to quantify the crush/crash characteristics of foam-filled hat-section components with respect to the changes in the afore mentioned design variables. Design charts are presented, from which design variables can be selected for particular applications in order to establish the weight effectiveness of foam reinforcement.
In the foam thickness range investigated (5–8 mm), the axially absorbed energy increased between 50–125%, while the maximum axial strength increased by 10–25% only. On the other hand, the flexural energy absorption increased from 10–40%, while the maximum bending load registered an increase ranging from 25 to 80%. Therefore, the use of thin gages accompanied by foam layers in the 5 to 8 mm range would result in the most efficient energy absorbing axial structural components. In addition, maximum bending strength can also be increased with almost no weight penalty, by deploying similar thicknesses of the epoxy-based foam in beam components. The cut-off gages for the efficiency of the epoxy-based foam (in the studied foam thickness layers of 5–8 mm) ranges from 1.4-1.8 mm for flexural applications and from 2.0–2.2mm for axial applications.
The enhancement in the structural characteristics of columns and beams through structural foam deployment, is due to a delayed local buckling mechanism. On the other hand, foam deployment in beams has to be enhanced in density and location, where plastic hinges are likely to form. This enhancement in location will minimize the total weight of the component thus maximizing the total specific energy gain per that member.
|Technical Paper||Effect of Polyurethane Foam on the Energy Management of Structural Components|
|Technical Paper||Effectiveness of Polyurethane Foam in Energy Absorbing Structures|
|Technical Paper||State-of-the-Art-Vehicle Structural Crashworthiness|
CitationAlwan, J., Wu, C., and Chou, C., "Effect of Epoxy-Based Structural Foam on Energy Management: An Experimental & Analytical Investigation," SAE Technical Paper 2001-01-0473, 2001, https://doi.org/10.4271/2001-01-0473.
SAE 2001 Transactions Journal of Passenger Cars - Mechanical Systems
Number: V110-6 ; Published: 2002-09-15
Number: V110-6 ; Published: 2002-09-15
- Porsche, Porsche Engineering Services, Inc., DN5 Lightweight Study, Final Report, March 30, 1993.
- Bores, A. P. and Sidebottom, O. M., “Advanced Mechanics of Materials”, 3rd Edition, 1978, John Wiley and Sons, New York, pp.670.
- Mahmood, H. F., and Paluszny, A., “Design of Thin Wall Columns for Crash Energy Management-Their Strength and Mode of Collapse”, Transactions SAE, 90, 4039, 1981.
- Abed, S. H., and Doane, R. M., “An Analytical Approach To Predict Maximum Bending Strength of Thin-Walled Beams Composed of High and Mild Strength Steel”, Technical Report No. ASE-93-04, Ford Motor Company, Alpha Simultaneous Engineering, May, 1993.
- Lampinen, B. E., and Jeryan, R. A., “Effectiveness of Polyurethane Foam in Energy Absorbing Structures”, Technical Report No. SR-82-55, Ford Motor Company, May, 1982.
- Thornton, P. H., “Energy Absorption by Foam Filled Structures”, SAE Technical Paper Series, Congress and Exposition, Detroit, Feb., 1980.
- Montgomery, D. C., and Analysis of Experiments, New York, John Wiley and Sons, 1991.
- Walpole, R. E., and Raymond, H. M., Probability and Statistics for Engineers and Scientists, 4th Edition, New York, Macmillan Publishing Company, 1989.
- LS-DYNA3D Users Manual, Livermore Software Technology Corportion, 1994.
- Lilley, K., and Mani, A., “Roof-Crush Strength Improvement Using Rigid Polyurethane Foam”, SAE, Topics in Vehicle Safety Technology, SP-1139, Feb. 1996, pp. 35–45.
- Chou, C. C., Zhao, Y., Lim, G. G., Patel, R., Shahab, S., and Patel, P., “Comparative Analysis of Different Energy Absorbing Materials for Interior Head Impact”, SAE paper No. 950332, 1995.
- Bilkhu, B. B., Founas, M., Nusholtz, G. S., and Du Bois, P., “Techniques fo Numerical Modelling of Cellular Materials using Material Models #5, #10, #41 in LS-DYNA3D”, The Second International LS-DYNA3D Conference held in San Francisco, September 20–21, 1994. Paper No. 2IL - SD3D104.
- Chang, F.S., Hallquist, J. O., Lu, D.X., Shahidi, B.K.,Kudelko, C. M., and Tekelly, J. P., “Finite Element Analysis of Low-Density High-Hysteresis Foam Materials and the Application in the Automotive Industry”, SAE Paper 940908, 1994.
- Alwan, J. , Wu, C.C., and Chou, Clifford,“ Effect of Polyurthane Foam on The Energy Management of Structural Components”, SAE 2000-01-0052, Feb. 2000, Detroit.